1. Field of the Invention
The present invention relates to an axial urging mechanism, and particularly to an urging mechanism, which can be operated and controlled by way of a hand to actuate a pressing device disposed at both ends of a pivotal shaft so as to urge or release a support device and a connecting seat between the two pressing devices synchronously for locating or adjusting both the support device and the connecting seat.
2. Description of Related Art
Often in our daily life, we encounter a mechanical structure formed of two articles with a respective connecting end being passed through with a pivotal shaft to generate a relative movement between the articles. An arrangement with regard to two articles moving relative to each other generally can be classified into three different types, that is, a fixed type, a moving type, and an adjustment type. The fixed type structure utilizes a conventional joint such as a welding joint to maintain both articles in a state of being fixedly located after the connecting ends of the two articles are passed through with the pivot shaft. The moving type structure applies another conventional joint such as a rivet joint to allow both articles to move relative to each other after the connecting ends of the two articles are passed through with the pivot shaft. The adjustment type structure uses a further conventional way such as a thread screw connection to fasten or loosen both of the articles so as to locate the articles or make an adjustment after the connecting ends of the two articles are passed through with the pivot shaft. Accordingly, a joint for two connecting articles can be presented with different structures based on different applications.
Taking a keyboard stand as. an example, the basis of a design for the keyboard stand has included a concept of an omni-bearing in recent years, that is, in addition to the most basic functions such as pushing forward and pulling backward, the keyboard stand can provide further functions such as going up and down, displacing to the right and to the left, and adjusting the elevation angle. Indeed, this design has brought a great convenience to the user. For instance, U.S. Pat. Nos. 5,839,984, and 6,186,460B1 owned by the present inventor have disclosed an axial urging device respectively and these urging devices basically provide a threaded rod passing through and connecting with two articles, a pressing lever fitting with a movable end of the threaded rod, and an adjusting knob engaging with the threaded rod. When the urging device is going to be adjusted, the user has to turn the adjusting knob with a hand to loosen the articles, and by means of the pressing lever and the other hand of the user holds the articles, which intend to move, so that height thereof can be lifted or descended and the elevation angle thereof can be adjusted. As soon as the articles have been moved to a desired location, the adjusting knob is tightened such that the articles are located firmly. This kind of urging device has been utilized for years and even is applied in U.S. Pat. Nos. 5,257,767 and 5,924,666. However, the prior art has involved a common defect that both hands of the user have to be in use at the same time during the urging device being operated and this is troublesome and inconvenient.
An object of the present invention is to provide an axial urging mechanism, which has a support device, a connecting seat, a pivotal shaft, and a pressing device such that the connecting ends on the support device and the wing ends on the connecting seat can be tightened or released for adjusting with a single hand.